With a rise in brain injuries among NFL players in recent years, the NFL has looked for new technology to make helmets better than ever before. A new study, published today in the Journal of Neurosurgery proves that the helmets are indeed getting better, Smithsonian reports.

The study was conducted by researchers from Virginia Tech using an automated head impact simulation system to test how two vintage Hutch H-18 leather helmets from the 1930s matched up to 10 plastic helmets currently in use. They found that, depending on how strong the impact was, the newer helmets performed better by anywhere from 45 to 96 percent.

The researchers used a model head with sensors inside, and dropped it from a range of heights between 12 and 60 inches. They made sure to hit the head in the front, back, top, and side in order to simulate real life impacts, and found that the plastic helmets performed much better than the leather ones. From 12 inches, the plastic helmets reduced impact by 59 to 63 percent, and from 36 inches, there was a 67 to 73 percent reduction. The researchers didn't try dropping the heads with leather helmets from 48 or 60 inches out of fear of damaging them.

This is good news considering that in 2011 another study said the complete opposite. According to the Smithsonian, a 2011 study found that many types of impacts weren't better for the head when using newer helmets. The study, however, was performed by smashing two helmeted heads together, one with the plastic helmet on and the other with the leather helmet on.

The authors of this new study believe that the way the 2011 study was performed distorted the findings and masked the differences between helmet types. They also say that padding in the plastic helmets absorbed some of the impact when the leather one was being tested.

What makes this study so contradictory to the 2011 one, the Smithsonian says, is that both studies accounted for the same factors. All leather helmets tested were about 80 years old, which could have meant weaker fibers in the leather. Also, all plastic helmets were unused.